Daily intake of supplemental beta-carotene for a minimum of 10 weeks contributes to sunburn protection, finds a meta-analysis by German scientists.

Following increasing concerns about the detrimental effects of sunlight on our skin and scientific trends towards nutritional protection against sunburn, Wolfgang Köpcke and Jean Krutmann from Münster University Hospital and Heinrich-Heine University-Düsseldorf ran a literature search to evaluate the effectiveness of the antioxidant carotenoid beta-carotene suggested to be protective.. The researchers used data from seven placebo-controlled clinical studies, i.e. studies in which the effectiveness of the substance in question is evaluated against an inactive substance. The trials covered a total of 135 people studied for 3 to 24 weeks with daily and total doses of supplemental beta-carotene in the range of 15 180 mg and 840 12,600 mg, respectively.

The meta-analysis showed that oral supplementation of beta-carotene protects against sunburns, with a maximum attainable sun protection factor of 4. This effect was not dependent on the quantity of beta-carotene, but on the duration of supplementation. More specifically, a minimum period of 10 weeks seems to be required for relevant protection and longer periods may yield better results.

However, the authors stressed that beta-carotene supplementation should not replace conventional sunscreens. Whereas oral intake of beta-carotene can provide protection at all times and to the whole skin, sunscreens are faster and stronger. Thus, these two protection methods should complement and not replace each other.

The main food sources of beta-carotene are yellow and green (leafy) vegetables such as spinach, carrots and red peppers, and yellow fruit such as mango, melon and apricots. Following the recommendation of eating five servings a day of fruits and vegetables would provide beta-carotene amounts similar to the lower supplemental doses used in the studies evaluated.

Smokers need to be aware that long-term high dose (≥20 mg) beta-carotene supplements may increase their lung cancer risk.

For more information, see:
Köpcke W and Krutmann J (2008) Protection from sunburn with beta-Carotene--a meta-analysis. Photochemistry and Photobiology 84(2):284-8

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